I'm probably overthinking this, but...
I recently started EDC'ing a Shield 9mm (love it!) and stoke it w/HST 124gr (I really like it's tested performance out of shorter bbl.'s) and always carry 2x8rd reloads.
However, I'm a proponent of shot placement & sufficient penetration w/all else being secondary.
For that reason, I carry Hornady 135gr Critical Duty in my larger 9mm's for the assured penetration at the cost of some expansion.

Now, I don't expect to find myself in any gunfights, much less gunfights requiring 1-2 reloads.
However, like insurance on my car, I'd rather play it safe and have too much than not enough.
If in a situation where I find myself reloading at least once, should I stick w/HST in my reloads or switch to the Critical Duty to better handle chance barriers (ie: BG's seeking cover after my first mag)?

What's the hive's collective consciousness say?

Tomac

You are over thinking it. Either of those bullets will take care of the problem should you need them. I personally carry gold dots because I've seen what they do to the human body.

I wouldn't worry too much about it because HST is a good all-around choice and while it is not best with barriers it still does pretty well with most handgun barriers. That said, personally I would carry the more barrier-blind round in the backup mags just in case the bad guy is hiding behind a vehicle or something and you aren't dead yet. I would be interested in your thoughts regarding this article by the Buffalo Bore owner as it is on this subject. What do you think? https://www.buffalobore.com/index.php?l=product_list&c=174

Everything is a compromise, personally I carry a bullet that penetrates more than HST but I would agree it is a very good bullet that expands in shorter barrels.

I voted other.

147 grain HST will perform better from a shorter barrel than the 124s.

Very interesting article, on the whole I have to agree w/it.
One item rarely mentioned is even if a bullet attempts to exit a body, it's like trying to penetrate an additional 4" of ballistic gel which considerably lessens the risk of overpenetration.

I currently have a fair amount of 124gr HST, 135gr Critical Duty and several thousand rds of 124gr FMJ for training.
A training advantage to carrying the HST is a very similar recoil impulse to the training ammo I have on-hand. I may need to do more testing w/the 135gr CD to see how the recoil impulse compares to my training ammo.

Tomac

Perhaps, but I can't find anything lacking in these results:


Here's the 147gr HST:


135gr Critical Duty:



Tomac

ETA: The Critical Duty ballistic gel test results would seem to indicate it's a poor choice out of shorter bbls.

I use the 150 Micro HST in my Shield. 147 standard pressure HST would be my next choice if I ran out of the 150's.

@Tomac I like the 124gr in the test you linked, it penetrates better than the 147gr and I would probably prefer it over the 147 although I think both did well. I had watched this video before but forgot the 124gr penetrated so well.

To me the 20-21in the Critical Duty does is not really that bad, a few inches over the 'recommended' but it's not going 30in either, they barely expanded but the shape is going to cause a wound tract much differently than a round nose FMJ. For a backup mag round intended for barriers it still seems like a good choice (based on that test). I'd take it over the HST if I were in a shootout around cars (hopefully wouldn't be lol)

In my short barrel 9mm I usually carry 147gr XTP +P, which seems to penetrate about like the critical duty in the test above does.

I don't think you can say one is definitely better overall than the other when comparing the 124g and 147g HST's.

One penetrates slightly deeper while the other expands slightly wider.

You are right, I was sort of getting off topic about what I would buy right now :)

Both are very impressive I'd really like to see some of the newer Corbon DPX out of a barrel that short as well.